Method of fabricating multiple glazing unit



April 30, 1968 c. E. STROUD ET AL 3,380,145

METHOD OF FABRICATING MULTIPLE GLAZING UNIT Original Filed Jan. 8, 19642 Sheets-Sheet 1 INVENTORS CHARLES E. 5T0U0 HERBERT C. CEEUTTI 77YOMA9/1- HUGHES April 30, 1968 c. E. STROUD ET AL METHOD OF FABRIGATINGMULTIPLE GLAZING UNIT 2 Sheets-Sheet 2 Original Filed Jan. 8, 1964United States Patent 3,380,145 METHOD OF FABRICATING MULTIPLE GLAZINGUNIT Charles E. Stroud, Natrona Heights, and Herbert C.

Cerutti and Thomas H. Hughes, Sarver, Pa., assignors to Pittsburgh PlateGlass Company, Pittsburgh, Pa., a corporation of Pennsylvania Originalapplication Jan. 8, 1964, Ser. No. 336,600, now Patent No. 3,280,523,dated Oct. 25, 1966. Divided and this application Aug. 2, 1965, Ser. No.476,506

3 Claims. (Cl. 29411) This is a division of application Ser. No.336,600, filed Ian. 8, 1964, now Patent No. 3,280,523.

This invention relates to method of fabricating a multiple glazingwindow unit and more particularly to a method of fabricating an elementfor spacing two glass sheets of such a unit from each other about theperiphery of the unit.

Multiple glazing units comprise two or more sheets of glass spaced fromone another to provide an insulating air space between the sheets. Thisair space is effective for reducing the passage of heat through the unitdue to conduction and convection. The sheets of glass are spaced fromeach other by a marginal edge spacing element. The glass sheets areadhered to the spacer element by a mastic composition applied in acontinuous film around the edges of the sheets between each sheet andthe spacing element to provide a hermetic seal, Preferably, theperipheral edges of the glass sheets forming the multiple glazing unitare protected by outwardly extending flanges of the spacing element orby a separate metal channel member of U-shaped cross section that isaflixed over the edges of the assembled unit. The spacing element aregenerally tubular in shape and filled with a desiccant. Openings in thespacing element communicate between the air space of the unit and theinside, tubular portion, of the element so that moisture from the airwithin the unit will be absorbed.

One conventional method of assembling multiple glazing units is to applya layer of bead or mastic along two opposite sides of the spacingelement, which sides are adapted to engage the inner surfaces of theglass sheets about the marginal edges. The spacing element is thenplaced between two precu-t glass sheets and the sheets are pressedtogether to adhere the sheets to the spacing element and to seal theinternal air space between the sheets from the atmosphere. The final airspace between the two glass sheets is a function of the thickness of thespacing element and the thickness of the mastic layers between each sideof the spacing element and the adjacent glass sheet.

In the fabrication of a multiple glazing unit as above described, thepressing operation often squeezes the mastic from between the glasssheets and the spacing element and into the viewing area of the unitinwardly of the marginal edges. Because the mastic is opaque, the effectis unsightly.

The spacing element of the present invention is constructed to preventthe inward flow of mastic into the viewing area of the unit during thepressing operation and, to this end, includes a pair of flanges alongthe outside of a tubular spacing element that are adapted to bepositioned between the two glass sheets of the unit inwardly of themarginal edges. These flanges extend along the lateral sides of thespacing element and are bent outwardly from the element to contact theinner surfaces of the glass sheets. The flanges are bent outwardly adistance sufficient to assure their contact with the facing surfaces ofthe spaced glass sheets before the mastic is squeezed into the viewingarc-a during the pressing operation. The flanges are .sullicientlyflexible that they yield 3,380,145 Patented Apr. 30, 1968 "ice inresponse to the pressing operation, permitting the glass sheets to bepressed closer together. As a result, the mastic is spread to provide athin, but relatively wide and, hence, effective seal between the spacingelement and the glass. As the mastic spreads, the flanges provide anefiicient dam against the inward flow of the mastic into the visiblearea of the unit. Because only the flanges yield, while the tubularspacing portion of the element remains rigid, the element may befabricated from a very light weight, thin, material and yet form a veryrigid and strong structure. In addition, the yielding of the flangesextends the width (i.e., distance inwardly from the marginal edges) ofthe mastic forming the vapor seal so that a wide but thin band is formedthrough which any moisture must permeate before reaching the interiorair space of the unit. The width assures a long moisture resistant pathand the thinness minimizes the critical zone through which moisturetends to permeate. In addition, the construction of this unit lendsitself to a maximum economy of fabrication, materials and equipment.Such economy is attained through the use of rolling equipment forshaping the spacing element to form a unitary element that may be cut tolength, notched to form mitered corners for the desired rectangularshape, and filled with a desiccant, all in a continuous operation.

Other advantages of the invention will become apparent from thefollowing detailed description of certain embodiments thereof taken inconjunction with the drawings in which:

FIG. 1 is a fragmentary, perspective view, partly in section, of amultiple glazing unit embodying the principles of the invention andomitting, for clarity, an optional edge-covering tape;

FIG. 2 is a fragmentary sectional view of the multiple glazing unit ofthe type shown in FIG. 1 prior to the pressing operation that results inthe finished unit shown .in FIG. 1;

FIG. 3 is a sectional view of the second embodiment of a spacing elementembodying the principles of the invention;

FIG. 4 is a sectional view of a third embodiment of a spacing elementembodying the principles of the invention;

FIG. 5 is a sectional view of a fourth embodiment of a spacing elementembodying the principles of the invention;

FIG. 6 is a fragmentary sectional view of a multiple glazing unit of adifferent type from that shown in FIGS. 1 and 2 and shows a fifthembodiment of a spacing element embodying the principles of theinvention;

FIG. 7 is a fragmentary perspective view of the spacing element of FIG.2 after forming but prior to being assembled into a rectangular shape;

FIG. 8 is a schematic process diagram illustrating a preferred processof forming the spacing element of FIG. 7; and

FIG. 9 is a sectional view of the spacing element of FIG. 7 showing anintermediate shape during the forming process.

In the drawings, and with particular reference to FIG. 1, a multipleglazing unit 12 is shown comprising two sheets of glass 14 and 16arranged in parallel relationship. The glass may be tempered, colored,laminated or have other special strength or optical properties. Theglass sheets are separated at their marginal edges of a continuousspacer element 18. The spacer element 18 includes a tubular portion ofrectangular cross section that is filled with a desiccant 20. An exampleof a suitable desiccant is granular or powered silica gel. Communicationbetween the air space between glass sheets 14 and 16 and the desiccant20 is provided through holes 21 in spacer element 18. The spacer element18 extends completely about the unit 12 and between the marginal edgesof the glass sheets.

The spacer element 18 is adhered to the glass sheets 14 and 16 at theirinner faces by means of a thin continuous film of an adhesive, moistureresistant, mastic composition 22. Curable synthetic polymeric adhesivesealants, such as initially flowable, cure-in-place, polysulfide basedsealants, are suitable for this purpose.

Spacer element 18 is formed of a continuous strip of thin metal, such asan aluminum alloy, preferably of a thickness between 0.004 and 0.015inch. At these thicknesses, the metal is readily formable, is moistureimpervious and is sufficiently rigid for its intended purpose whenformed in the shapes herein disclosed. The metal is bent in the generalform of a tubular member having a flat side 24 of a single thickness ofmetal with flanges 26 and 27 along each edge of flat side 24 in the sameplane thereof and formed by bending the metal of flat side 24 back uponitself for a distance equal to the desired width of the flanges. Twospaced sides 29 and 30 of sapcer element 18 are formed of a singlethickness of metal and perpendicular to flat side 24 at the junctures offlanges 26 and 27. The spaced sides 29 and 30 are formed by bendingextensions of the sheet of metal forming flat side 24 and flanges 26 and27 at right angles from the terminal portions of flanges 26 and 27.

Two additional flanges 32 and 34 at the distal ends of the two spacedsides 29 and 30 are formed from the sheet metal of each of the twospaced sides by bending the metal of each back upon itself a distanceequal to the desired width of the flanges. The flanges 32 and 34 extendin a direction generally away from flanges 26 and 27, and inwardly ofthe marginal. edges of a unit 12. They are also bent outwardly from theplanes of the spaced sides 29 and 30 relative to the unit 12 at an angleless than 90 degrees so that they diverge from each other and contactthe inner surfaces of glass sheets 14 and 16. A web 36 extending fromthe flange 34 spans the distance between spaced sides 29 and 30,parallel to flat side 24 but spaced therefrom, and is located at thejunctures of flanges 32 and 34 and their respective spaced sides 29 and30. A terminal portion 37 of web 36 is located between the twothicknesses of sheet metal forming flange 32. Flanges 32 and 34 are eachknurled on their inner facing surfaces, as at 38, to provide rigidity.

The web 36 contains spaced apertures 21 providing passageways allowingcirculation of air between the air space of the unit and the desiccantchamber in spacing element 18. This construction provides openingscontrolled in size and independent of the position of the sides orflanges of the spacing element, and thereby substantially eliminates theescape of fine particles of desiccant into the visual area of the unit12.

Flanges 32 and 34, by virtue of the thin metal of which the spacingelement is constructed and the bracing afforded by web 36, are flexibleabout the juncture of web 36 and spaced sides 29 and 30. Thesignificance of this relationship may be better appreciated inconnection with FIG. 2 disclosing the spacer element 18 and the glasssheets 14 and 16 just prior to the pressing operation that forms thefinished unit shown in FIG. 1.

As shown in FIG. 2, the mastic composition 22 has been applied toelement 18 adjacent flanges 26 and 27 and spaced sides 29 and 30. Themajor portion of the mastic is located close to flanges 26 and 27. Innerflanges 32 and 34 are bent outwardly from the planes of spaced sides 29and 30 at an angle, preferably of between about 30 to 60 degrees, but inall events less than 90 degrees. The flanges 32 and 34 extend a distancesuflicient to facilitate their contacting the inner surfaces of glasssheets 14 and 16 before there is substantial displacement of mastic 22by the glass sheets during the pressing operation, Glass sheets 14 and16, in the relationship shown in FIG. 2, are pressed towards each otherto form the 4 unit shown in FIG. 1. Movement of the glass sheets bendsflanges 32 and 34 about the corners formed by spaced side walls 29 and30 and web 36. As the movement of the glass sheets diminishes the spacebetween the side wall 29 and the glass sheet 14, and the side wall 30and the glass sheet 16, the mastic flows inwardly of the peripheraledges of the unit towards flanges 32 and 34 and the visual zone of theunit. However, contact between the glass sheets and the tips of flanges32 and 34 prevents the flow of the mastic beyond the zone of contactand, instead, any excess mastic is force to escape beneath flanges 26and 27. As flanges 32 and 34 straighten, the width of the vapor sealprovided by the mastic 22 increases and the thickness decreases. A widthof at least A inch has been found desirable, and the straightening offlanges 32 and 34 facilitates maximum width. The thickness of the masticwill vary across the width of the seal because the pressing pressureoften causes a slight dishshaped deformation in side walls 29 and 30.Preferably, the mastic thickness will not be greater than 0.010 inch andin any event not thicker than 0.025 inch. The mastic thickness over mostof the width of the seal is less than 0.005 inch.

It has been found desirable to apply a thin, flexible, film of adhesivetape 39 about the periphery of the unit 12, as shown in FIG. 2, torestrain any excessive outward flow of mastic from beneath flanges 26and 27. For clarity, this tape, the use of which is optional, has beenomitted from the finished unit shown in FIG. 1.

FIGS. 3, 4, and 5 disclose alternative ways of constructing a spacerelement to have the same general configuration of spacer element 18.Thus, in FIG. 3, a spacer element 18a is constructed in the same manneras spacer element 18 except for flange 32a, which is formed by doublingthe terminal portion of web 36a over a terminal portion of side 29a. InFIG. 4, a spacer element 18b is shown of the same configuration asspacer element 18 but formed of two separate pieces. Sides 24b, 29b and30b are formed of one piece and web 36b is formed of a separate piece.Terminal portions of web 36b are clamped along each side within theterminal portions of sides 2% and 30b that are bent back upon themselvesto form flanges 32b and 34b.

The embodiment of FIG. 5 shows a spacer element of the same generalconfiguration as spacer element 18 but with the closure of the tubelocated at flange 260 instead of at flange 32 as in FIGS. 1 and 2. Itwill be evident from this embodiment that the tubular spacing elementmay be joined at any corner. Alternatively, the element 180 could beformed of two separate pieces of metal. Flat side 240 could be formed ofa single piece of metal with longitudinally extending edges bent backupon themselves to form both flanges 26c and 27c at terminal portions inthe manner now shown only at 26c in FIG. 5. Spaced sides 29c and 300,flanges 32c and 34c and web 360 would then all be formed from a secondpiece of metal and joined with flat side 240 by terminal portionsclamped between the folded back portions of flanges 26c and 270.

It will be readily understood that, while flat sides 29 and 30 providethe thinnest mastic layer and, hence, diminish the opportunity for vapordiffusion and provide resistance to compression along their entirelength due to web 36 and the desiccant 20, the sides may be curved orsloped while still utilizing flanges 32 and 34 to prevent the inwardflow of mastic. It is also contemplated that spacing element 18 may beextruded, or formed to the desired shape from tubular stock rather thanfrom a sheet or ribbon, and in either case have no seams or terminalportions to be joined.

An embodiment of different configuration is shown in FIG. 6 of thedrawings. This embodiment is similar to the embodiment of FIGS. 1 and 2but omits outer flanges 26 and 27. Thus, a spacer element indicatedgenerally at 44 is formed of a single sheet of thin material such asaluminum sheet or foil and bent to form a generally rectangular-shaped,tubular, spacing element. A flat side 46 and two spaced sides 48 and 50extending in the same direction therefrom and perpendicular thereto, anda web portion 52 parallel to flat side 46 but spaced therefrom, form arectangular tube. A flange 53 extending from the juncture of side 50 andweb 52 is formed by bending the metal forming side 50 outwardly of theplane of the side at an angle less then 90 degrees and then back uponitself for a distance equal to the desired length of the flange. Web 52is then formed by an extension of the metal forming flange 53. A flange54 is formed at the juncture of side 48 and Web 52 by bending the metalforming side 48 outwardly from the plane of the side at an angle lessthan 90 degrees and then back upon itself for a distance equal to thedesired length of the flange. A terminal portion 55 of Web 52 is engagedbetween the folded back portion of the metal forming flange 54 tocomplete the element. Mastic 56 between the sides 48 and 50 and theadjacent glass sheets 57 and 61 adheres the parts together and forms amoisture impervious seal in the same manner as disclosed with referenceto FIGS. 1 and 2. Flanges 53 and 54 function in the same manner asflanges 32 and 34.

Where desired, a channel member 58 of U-shaped cross section may beaffixed around the periphery of the unit of FIG. 6. The channel member58 is made of metal, such as stainless steel. The angle that the flangesor sides of the channel member form with the central portion is slightlyless than 90 degrees. When the channel member is aflixed to the edges ofthe glass sheets, these sides are held apart to allow the glass to beinserted therein. The sides are then released and they spring back intocontact with the faces of the glass sheets. The channel members are thusheld on under tension. A resilient, moisture resistant, strip 59 with alayer of mastic 60 adhered thereto is preferably placed between thechannel member 58 and flat side 46 of spacer element 44 about theperipheral edges of the glass sheet.

FIG. 7 illustrates the construction of the spacer element 18 thatfacilitates the continuously formed tubular spacer element to befabricated into a rectangular shape. The continuous element 18 isnotched as at 62 at three spaced intervals corresponding to the desireddimensions of the finished unit. The angle of the V of notches 62 is 90degrees and the apex of the V of the notch terminates at the juncture offlanges 26 and 27 and their respective sides 29 and 30. Flat side 24 isthen bent until the two edges of each V-shaped notch 62 meet each otherto form a mitered corner. Each end of the spacer element 18 is cut at 45degrees and at one end flat side 24' extends beyond side walls 29 and 30to form a terminal flap 64. This flapfolds over the other terminal endof the continuous spacer element 18 when the two ends are placed inabutting relationship to form the fourth corner of the rectangular unit.Flap 64 is then fastened in the position shown in FIG. 1 with mastic at65.

At each of the three notches 62 a plug 66 of flexible, rubber-likematerial is inserted in the position shown in FIG. 7. Plug 66 isessentially of the same cross-sectional shape as that of the tubularportion of the spacing element 1-8. One end 67 is aligned with the apexof the associated notch 62 so that the notch is substantially sealedfrom the desiccant when the spacing element is bent at right angles ateach notch. As will be explained below, the desiccant is temporarilyrestrained within element 18 by mastic placed in each corner duringfabrication. A bent plug 68 of like construction to plug 66 seals themastic and desiccant at each end of element 18 when the terminal endsare placed in abutting relationship. A hole 70 allows air within theunit 12 to escape through the corner as the air space is diminishedduring the pressing operation. Flow of mastic 22 by the completion ofthe pressing operation and mastic 65 of flap 64 prevent furthercommunication between the ambient atmosphere and the air space throughhole 70 once flap 64 is sealed.

The process by which the spacing element 18 is constructed and themultiple glazing unit 12 fabricated may be best understood in connectionwith the schematic processing layout shown in FIG. 8.

A continuous ribbon of metal is fed from a coil 76 through rolling dies78 and progressively formed by conventional techniques into the crosssectional channel shape shown in FIG. 9. Particulate desiccant isdeposited into the channel from a hopper 80 to a level substantiallyeven with the junctures of flanges 32 and 34 with walls 29 and 30. Thedesiccant, by substantially filling the spacing element 18 (i.e.,filling at least 80 percent of the volume and, preferably, at least 90percent) lends additional strength and rigidity to the unit. Subsequentrolling dies 82 close web 36 to form a tubular member of the shape shownin FIG. 2. Knurl marks 38 and holes 21 are formed during this subsequentrolling operation.

A desired length of the formed tubular spacing element 18 is severed ata 45 degree angle, leaving an extending flap 64-, and right angleV-notches 62 are cut in sides 29 and 30 by spaced cutting dies 83, 84,85 and 86 in a conventional manner. Because of the additional rigidityimparted to element 18 by the desiccant, there is little or nodistorting of the spacing element from the cutting dies. During thenotching and severing operation, a mastic composition is extruded intothe tubular portion of element 18 at each notch and at the severed endto temporarily restrain the desiccant from escaping.

A bead or layer of mastic is next applied along sides 29 and 30 ofspacing element 18 as it moves past beading applicators indicated at 88.A plug 66 is then manually inserted into each of the three notches 62and a bent plug 68 is inserted into one end of the element 18. Theelement 18 is then manually bent to a rectangular shape by folding it ateach notch and is placed upon a horizontally disposed, pre-cut glasssheet about the marginal portion of the upper surface thereof. A secondpre-cut sheet of glass of similar shape and dimensions to the first isthen placed upon the spacing element in superposed relationship with thelower sheet. Preferably, a strip of flexible adhesive tape is appliedabout the periphery of the assembled unit. The sheets of glass arepressed toward each other to adhere them to the spacing element and toseal the inside air space from the ambient atmosphere.

Although the present invention has been described with particularreference to the specific details of certain embodiments thereof, it isnot intended that such details shall be regarded as limitations upon thescope of the invention except insofar as included in the accompanyingclaims.

We claim:

1. In a method of forming a rectangular spacing element having miteredcorners for a multiple glazing unit, the steps comprising forming achannel having a base, two extending sides and an open portion orientedupwardly; depositing desiccant into said channel through said openportion; closing said channel to form a tube containing the desiccant;cutting three 90 degree notches at spaced locations along said tube; andbending said tube at right angles at the three notches to form arectangular spacing element.

2. In a method of forming a spacing element for a multiple glazing unit,the steps comprising forming a channel having a base, two extendingsides and an 0 open portion oriented upwardly; depositing desiccant intosaid channel through said open portion; closing said channel to form atube containing the desiccant; thereafter severing a portion of saidtube from a remaining portion at a 45 degree angle and cutting three 90degree notches at spaced locations along said tube; extruding a masticinto said tube at each severed and notched portion to retain thedesiccant Within the tube; inserting a separate plug into said tube atwhich of the three notches and at one of the severed ends; and bendingsaid tube at right angles at the three notches to form a rectangularspacing element.

3. In a method of forming a multiple glazing unit, the steps comprisingforming a spacing element by continuously and progressively roll forminga moving thin sheet or ribbon of malleable material into the generalform of a longitudinally extending channel having a base, two extendingsides and an open portion oriented upwardly; depositing a particulatedesiccant into said channel through said open portion, closing saidchannel to form a tube containing the desiccant, thereafter severing aportion of said tube from a remaining portion at a 45 degree angle andcutting three 90 degree notches at spacer locations along said tube,extruding a mastic into said tube at each severed and notched portion toretain the desiccant within the tube, inserting a separate plug intosaid tube at each of the three notches and at one of the severed ends,applying a layer of mastic on two opposite sides of the spacing elementalong the length thereof, bending said tubes at right angles at saidthree notches to form a rectangular spacing element, forming an assemblyby placing said spacing element upon a first pre-cut, rectangularshaped,sheet of glass with the element adjacent marginal edges of the sheet,placing a second similar sheet of glass upon the spacing element insuperposed relationship "to the first sheet, applying a flexibleadhesive tape about the periphery of the assembly and thereafterpressing the W0 sheets of glass toward each other to seal the sheets tothe spacing element with the mastic.

References Cited UNITED STATES PATENTS 1,836,354 12/1931 Abrams 294761,913,205 6/1933 Lenhart 52172 2,219,595 10/1940 Lang 29476 2,127,618 8/1938 Riemenschneider 29417 2,742,690 4/ 1956 Kunkel 29417 3,030,6734/1962 London 52172 3,105,274 10/1963 Armstrong i 52--6l6'X 3,284,88911/1966 Flitman et a1. 29411 2,964,809 12/ 1960, Gwyn et a1 29-455 X3,212,179 10/1965 Koblensky 29-455 X CHARLIE T. MOON, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,380,145 April 30 1968 Charles E. Stroud e1: a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 6, line 74 "at which" should read Column 7 line 13, "sfaacer"should read spaced Signed and sealed this 23rd day of September 1969.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Ir.

Commissioner of Patents Attesting Officer

1. IN A METHOD OF FORMING A RECTANGULAR SPACING ELEMENT HAVING MITEREDCORNERS FOR A MULTIPLE GLAZING UNIT, THE STEPS COMPRISING FORMING ACHANNEL HAVING A BASE, TWO EXTENDING SIDES AND AN OPEN PORTION ORIENTEDUPWARDLY; DEPOSITING DESICCANT INTO SAID CHANNEL THROUGH SAID OPENPORTION; CLOSING SAID CHANNEL TO FORM A TUBE CONTAINING THE DESICCANT;CUTTING THREE 90 DEGREE NOTCHED AT SPACED LOCATIONS ALONG SAID TUBE; ANDBENDING SAID TUBE AT RIGHT ANGLES AT THE THREE NOTCHES TO FORM ARECTANGULAR SPACING ELEMENT.